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result(s) for
"Mauritius Colonization."
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Abacus and Mah Jong: Sino-Mauritian Settlement and Economic Consolidation
This case study of Chinese settlement in Mauritius investigates the complexities of colonial diasporas and sets the construction of a mythology of migration against the realities of the processes of negotiation and communication with the larger society.
eBook
Gecko phylogeography in the Western Indian Ocean region: the oldest clade of Ebenavia inunguis lives on the youngest island
Aim: We studied the gecko genus Ebenavia to reconstruct its colonization history, test for anthropogenic versus natural dispersal out of Madagascar, and correlate divergence date estimates of our phylogeny with geological age estimates of islands in the region. Location: Madagascar and surrounding islands of the Western Indian Ocean (Comoros, Mayotte, Mauritius, Pemba). Methods: We reconstructed the phylogeny of Ebenavia covering its entire geographical range using a molecular data set of three mitochondrial and two nuclear markers. We estimated divergence times based on calibrations using (1) previously calculated mutation rates of mitochondrial markers, (2) a combination of these rates with old or (3) young geological age estimates for some of the islands inhabited by the genus, and (4) an independent data set with fossil outgroup calibration points. Results: Ebenavia inunguis, one of two recognized species of the genus, comprises multiple ancient evolutionary lineages. The earliest divergence within this complex (Miocene, 13-20 Ma; 95% credibility interval [C1]: 4-29 Ma) separates the population of the Comoros Islands, excluding Mayotte, from all other lineages. The age estimates for island lineages coincide with the geological age estimates of the islands except for Grand Comoro, where the age of the local clade (3-5 Ma; 95% CI: 2-7 Ma) significantly predates the estimated island age (0-5 Ma). A clade from north Madagascar + Mayotte + Pemba is estimated to have diverged from an eastern Malagasy clade in the Miocene. Main Conclusions: Our results suggest that Grand Comoro Island is geologically older than previously estimated. The islands of the Comoros and Pemba were probably colonized via natural dispersal out of Madagascar (> 1000 km in the case of Pemba). Mauritius was most likely colonized only recently from eastern Madagascar via human translocation.
Journal Article
Community assembly and diversification in a species-rich radiation of island weevils (Coleoptera: Cratopini)
Aim: To test a prediction derived from island biogeographical theory that in situ speciation should make an increasingly important contribution to community assembly as islands age. This prediction is tested on estimated biogeographical histories from Mauritius (approximately 9 Myr) and Reunion (approximately 5 Myr). We additionally investigate the evolutionary dynamics of insect flight loss, as the loss of flight in island lineages can influence patterns of diversification. Location: Mascarene Islands; Southwest Indian Ocean. Taxon: Weevils. Methods: Up to five individuals of each taxonomically described species sampled within each sampling site were sequenced for the mitochondrial gene Cytochrome Oxidase II to delimit operational taxonomic units (OTUs). OTUs were further sequenced for the nuclear genes Arginine Kinase, Histone 3 and ribosomal 28s, to reconstruct the phylogenetic history of the group. Timings of colonization and in situ speciation events were estimated with BEAST2. Results: Our results support the hypothesis that present-day species richness on the older island of Mauritius is largely the result of in situ speciation, with few colonization events, of which all but the most basal are recent. In contrast, Reunion presents a more uniform temporal spectrum of colonization times. Flight loss has evolved convergently at least five times, and speciation events associated with flight loss are significantly younger than speciation events that have not resulted in flight loss. Main conclusions: Patterns of community assembly on the islands of Mauritius and Reunion fit a model where the addition of new species and species turnover is increasingly dominated by in situ speciation as an island community matures. Repeated flight loss indicates selection for flightlessness, with the young age of flightless lineages suggesting higher extinction rates over longer evolutionary timescales and little influence on present-day species richness.
Journal Article
Reunion Island, a sentinel territory for antimicrobial-resistant bacteria surveillance in the South-Western Indian Ocean: a retrospective survey using hospitalized patient screening, 2015–2017
Background
In 2015, antimicrobial resistance was identified as a public health priority for the South-Western Indian Ocean (SWIO) (i.e. Comoros, Madagascar, Mauritius, Mayotte (France), Reunion Island (France), and Seychelles). However, in 2020, colonization rates of antimicrobial-resistant bacteria (ARB) in human populations on most islands in SWIO were still not known and neither hospital nor community colonization rates had been estimated. The aim of this study was to estimate the prevalence of colonization of six ARB groups in hospitalized patients residing in the SWIO territories. The six groups comprise extended-spectrum betalactamase producing Enterobacteriaceae (ESBL-E), carbapenem-resistant Enterobacteriaceae (CRE), methicillin-resistant
Staphylococcus aureus
(MRSA), vancomycin-resistant enterococci (VRE), and both ceftazidime and/or imipenem-resistant
Acinetobacter
spp. (ACB), and ceftazidime and/or imipenem-resistant
Pseudomonas
spp. (PSA)).
Methods
Based on comprehensive hospital laboratory ARB screening data, we provide the first estimation of ARB colonization rates in hospitalized patients residing in SWIO (2015–2017). Using ARB colonization rates in Reunion Island (France) as the reference for estimating odds ratio, we identified at risk patients based on their territory of residence.
Results
The survey pointed to significantly higher overall ARB colonization rates in patients from Comoros, Madagascar, Mayotte, and Seychelles compared to Reunion Island as the reference. Extended-spectrum betalactamase producing Enterobacteriaceae was found to be the most common ARB group colonizing patients from SWIO territories. The highest MRSA colonization rates were observed in patients from Mayotte and Seychelles. Colonization by carbapenem-resistant Enterobacteriaceae (CRE) was highest in patients from Mauritius.
Conclusion
These results identify high ARB colonization rates in hospitalized patients from SWIO territories that require further investigation, particularly CRE in Mauritius and MRSA in Seychelles and Mayotte. This study is the first step toward the implementation of a broader regional ARB surveillance system.
Journal Article
Ancient DNA reveals the origins, colonization histories, and evolutionary pathways of two recently extinct species of giant scops owl from Mauritius and Rodrigues Islands (Mascarene Islands, south-western Indian Ocean)
Aim The islands of the south‐western Indian Ocean region are home to many endemic bird species, with their closest relatives occurring in Africa and Madagascar, Eurasia, the Sunda Islands, and the Australasian region. Among owls, the extant endemic scops owls (genus Otus) from Madagascar, Comoros, Seychelles, and Socotra are related to the Southeast Asian species, O. sunia, the Oriental scops owl. Three owl species, presumably Otus derivatives, twice the size of standard scops owls and now extinct, once inhabited the Mascarene Islands, and have been placed in a separate genus, Mascarenotus. Insular apomorphies have made their precise relationships difficult to determine. Here we investigate the phylogenetic position of these enigmatic owls. Location The Mascarene Islands (Réunion, Mauritius, Rodrigues) in the south‐western Indian Ocean. Methods Phylogenetic relationships were reconstructed using ancient DNA extracted from subfossil remains. Fragments of cytochrome b gene were amplified and sequenced. The ancient sequences were analysed with modern sequences of 19 ingroup Otus taxa using Bayesian and Maximum Likelihood methods. Results The Mauritian extinct species M. sauzieri was reconstructed as the sister to both O. pauliani (Grand Comoro) and O. rutilus (Madagascar). The Rodrigues extinct species M. murivorus was the sister, in a star‐like differentiation, to the preceding clade as well as the remaining Comorian species and a clade formed by O. insularis (Seychelles) and O. sunia. Main conclusions The ancestor of O. sunia simultaneously colonized Rodrigues Island (evolving into Otus murivorus), Madagascar, and part of the Comoros Islands around 3 million years ago. Later, presumably from Madagascar, new lineages colonized Grand Comoro and Mauritius (O. sauzieri). Independently, a more recent O. sunia ancestor colonized the Seychelles Islands and Socotra. These colonizations were probably favoured by Pliocene cyclonic events, stronger and more frequent than today. Several features, including giantism, wing reduction, and a relative decrease in skull and orbit size evolved convergently in the polyphyletic species O. sauzieri and O. murivorus.
Journal Article
Evolutionary patterns in the assembly of fern diversity on the oceanic Mascarene Islands
AIM: To provide insights into the assembly and structure of biotic communities by exploring several processes of island biodiversity assembly: in situ speciation, immigration and ecological processes. LOCATION: The Mascarene Islands. METHODS: The phylogenetic relationships of 211 out of 232 Mascarene leptosporangiate fern species were reconstructed in relation to a global phylogeny of 400 leptosporangiate fern species to assess the importance of immigration versus in situ speciation and any deviation from randomness. Correlations between speciation and habit (terrestrial or epiphytic/lithophytic) were tested. RESULTS: We inferred at least 197 colonization events onto the islands, accounting for > 80% of their leptosporangiate fern diversity. The phylogenetic structure of the assemblage of colonists was mostly overdispersed but aggregated at the tips of the phylogeny. Several families were more diverse on the islands than expected by their global richness. Among the 46 endemic species, up to 65% were inferred to have originated by cladogenesis, which in turn was found to be significantly related to a terrestrial habit. MAIN CONCLUSIONS: Immigration has played a major role in the assembly of the fern flora on the Mascarene Islands. The overdispersion pattern supports the hypothesis of a dominant role of competitive interactions in the flora assembly, and we propose that most available niches were filled by species arriving via long‐distance dispersal, preventing further immigration of closely related taxa. The over‐representation of some families may reflect better colonization capacities, preadaptation to the Mascarene ecological niches, or ecological differentiation. Frequent colonization by long‐distance dispersal has probably hampered in situ speciation in some habitats such as the epiphytic realm. Conversely, cladogenetic speciation appears to occur more frequently in terrestrial habitats.
Journal Article
High Risks of Losing Genetic Diversity in an Endemic Mauritian Gecko: Implications for Conservation
Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P. guimbeaui. We identified 18 threatened and 12 viable subpopulations and discuss a range of management options that include translocation of threatened subpopulations to retain maximum allelic diversity, and habitat restoration and assisted migration to decrease genetic erosion and inbreeding for the viable subpopulations.
Journal Article
Decolonizing Creole on the Mauritius islands: Creative practices in Mauritian Creole
Many Caribbean and Indian Ocean islands have a common history of French and British colonization, where a Creole language developed from the contact of different colonial and African/ Indian languages. In the process, African languages died, making place for a language which retained close lexical links to the colonizer’s tongue. This paper presents the case of Mauritian Creole, a language that emerged out of a colonial context and which is now the mother tongue of 70% of Mauritians, across different ethnic and linguistic backgrounds. It pinpoints the residual colonial ideologies in the language and looks at some creative practices, focusing on its oral and scribal aspects, to formulate a ‘decolonial aesthetics’ (Mignolo, 2009). In stressing the séga angazé (protest songs) and poetry in Mauritian Creole in the history of resistance to colonization, it argues that the language is, potentially, a carrier of decolonial knowledges.
Journal Article
The Welfare Implications of Using Exotic Tortoises as Ecological Replacements
Ecological replacement involves the introduction of non-native species to habitats beyond their historical range, a factor identified as increasing the risk of failure for translocations. Yet the effectiveness and success of ecological replacement rely in part on the ability of translocatees to adapt, survive and potentially reproduce in a novel environment. We discuss the welfare aspects of translocating captive-reared non-native tortoises, Aldabrachelys gigantea and Astrochelys radiata, to two offshore Mauritian islands, and the costs and success of the projects to date.
Because tortoises are long-lived, late-maturing reptiles, we assessed the progress of the translocation by monitoring the survival, health, growth, and breeding by the founders. Between 2000 and 2011, a total of 26 A. gigantea were introduced to Ile aux Aigrettes, and in 2007 twelve sexually immature A. gigantea and twelve male A. radiata were introduced to Round Island, Mauritius. Annual mortality rates were low, with most animals either maintaining or gaining weight. A minimum of 529 hatchlings were produced on Ile aux Aigrettes in 11 years; there was no potential for breeding on Round Island. Project costs were low. We attribute the success of these introductions to the tortoises' generalist diet, habitat requirements, and innate behaviour.
Feasibility analyses for ecological replacement and assisted colonisation projects should consider the candidate species' welfare during translocation and in its recipient environment. Our study provides a useful model for how this should be done. In addition to serving as ecological replacements for extinct Mauritian tortoises, we found that releasing small numbers of captive-reared A. gigantea and A. radiata is cost-effective and successful in the short term. The ability to release small numbers of animals is a particularly important attribute for ecological replacement projects since it reduces the potential risk and controversy associated with introducing non-native species.
Journal Article